The effects of stressed conditions on the accumulation of phenolic compounds by Penicillium sp. No. T4 and their subsequent antioxidant activities
胁迫条件对一土生青霉菌总酚积累及其清除自由基能力的影响

This study was designed to evaluate the effects of stress conditions on the accumulation of phenolic compounds by Penicillium sp. No. T4 in solid substrate and their subsequent antioxidant activities. H2O2, ultraviolet and medium of nutrition deficiency were used as oxidative stressors. Phenol levels were measured using Folin-Ciocalteu method. Capacities for scavenging free radicals were detected by spectrophotometric methods. The exposure of Penicillium sp. No. T4 to H2O2, at 1mmol/L or ultraviolet radiation for 40s and 50% nutrition deficiency substrate resulted in a higher production of phenolic compounds as compared with control, with levels reaching 63.86mg/g, 58.4mg/g and 43.19mg/g, respectively. Extracts from mycelia grown under stress conditions showed higher capacities for scavenging hydroxyl radical than other free radical, with a scavenging rate of 35.28% by the phenolic compounds from mycelia grown in 1mmol/L H2O2, 69.97% by those from mycelia under 40s ultraviolet radiation and 50.83% by those from mycelia under 75% medium nutrition deficiency. The results suggest that Penicillium sp. No. T4 accumulates more phenolic compounds under oxidative stresses and thereby enhances its resistance to oxidative stresses.